1. Field
Example embodiments relate to a semiconductor light emitting device and method of manufacturing the same. Other example embodiments relate to a nitride-based semiconductor light emitting device having increased efficiency and power characteristics using a relatively simple process and method of manufacturing the same.
2. Description of the Related Art
Research on light emitting devices using compound semiconductors, for example, GaN, AlN and/or InN semiconductor-based light emitting devices, has been conducted. Also, many light emitting devices including light emitting diodes (LEDs), laser diodes (LDs) and flat panel display (FPD) back lights (BLUs) have been developed.
Demand for increased luminance products using improved optical efficiency characteristics has increased. Thus, increased luminance products, to which increased currents are to be applied, are needed. Illumination light emitting devices are representative of increased luminance products. However, because an increased current is required to be applied to a nitride light emitting device of an increased luminance product, a relatively large amount of heat may be generated during an operation of the nitride light emitting device. The generation of heat may shorten the lifespan of the nitride light emitting device. Thus, a heat-resisting light emitting device may be developed as an illumination increased luminance light emitting device.
Light emitting devices using commonly used nitride semiconductors may be manufactured by growing nitride thin films on sapphire substrates. Thus, the sapphire substrates may remain integrated with the nitride thin films after the light emitting devices are manufactured. Because the sapphire substrates have lower thermal conductivity than the nitride semiconductors, heat generated during operations of the light emitting devices may not be sufficiently emitted. Thus, temperatures of the nitride thin films constituting the light emitting devices may increase, which may be a factor in reducing the lifespan and efficiency of the light emitting devices. Removing the sapphire substrates after the light emitting devices are manufactured may relieve the heat emission problem caused by the lower thermal conductivity of the sapphire substrates.
A laser lift-off (LLO) method may be used. In this method, a laser beam may be irradiated to melt nitride on an interface between a sapphire substrate and a nitride thin film so as to remove the sapphire substrate from the nitride thin film. If a LLO method is used, a sapphire substrate may be removed. However, a nitride thin film may be damaged by high heat generated in a LLO process, which may deteriorate an optical characteristic of the nitride thin film and may be inevitable in the LLO process.
Also, the nitride thin film may be fixed to epoxy to perform the LLO process. If the nitride thin film is not completely adhered to epoxy in this process, the nitride thin film may be cracked in a process of lifting off the sapphire substrate. The yield of the product may be greatly lowered, and it may be difficult to use the products due to a crack occurring in the nitride thin film.